52 less than twice a number written in algebraic expression

What term makes it inconsistent y=2x - 4 ?

What is the percentile for data value 6 in the following data set? 4 13 8 6 4 4 13 6 4 13 2 13 15 5 9 4 12 8 6 13 40 25 35 62

X+ y = 5 ; x - y =3 solve using linear combination